Arrange the following items in the order in which they receive electrons from glycolysis and TCA oxidations and harness the energy to establish a transmembrane proton gradient.

Arrange the following items in the order in which they receive electrons from glycolysis and TCA oxidations and harness the energy to establish a transmembrane proton gradient.

Oxidoreductase , NAD+ , Terminal oxidase , Quinone , Oxygen

1. NAD+

2. Oxidoreductase

3. Quinone

4. Terminal oxidase

5. Oxygen

Explanation:

NAD+ accepts electrons released during oxidation reactions of glycolysis and Kreb's cycle. NADH enters into ETC and gives its electrons to NADH dehydrogenase. NADH dehydrogenase is also called ubiquinone oxidoreductase or complex I.  

Complex I passes the electrons to complex III which is also called cytochrome bc1 complex (complex III) or quinone. Electrons from cytochrome  bc1 complex are passed to complex IV and then to terminal electron acceptor which is molecular oxygen.

Complex IV of ETC is also called terminal oxidase as it obtains electrons from cytochrome bc1 complex to the oxygen molecule. Complex I, III and IV of ETC pump 4, 4 and 2 protons towards the intermembrane space during the transfer of each electron pair.

answer///systemic;